[U-Boot-Users] R: Booting with attached BDI butnot alone (onlyICTRL remained in BDI cfg)

Andreas Schweigstill
2007-09-13T15:15:49Z

Hello!

Jerry Van Baren schrieb:
> Sounds like his board was damaged by operator error (improperly
> connecting to the BDI connector). My guess is that the pullup resistor
> lost its smoke.

I agree that the board may have been damaged by the operator. But
the pull-up resistor won't be damaged except from very high voltage.

Attaching a debug interface in the wrong direction probably may
destroy it if it gets its power supply from the target. If it has
its own supply (or gets it via USB from a PC) it can be possibly
that either negative voltages (target GND connected to debugger VCC)
or high voltages (target VCC connected to debugger GND) may be
applied to the JTAG/BDM signals on the target. Such voltages may
cause small defects to the silicon which show strange behaviour
afterwards.

Regards
Andreas Schweigstill

--
Dipl.-Phys. Andreas Schweigstill
Schweigstill IT | Embedded Systems
Schauenburgerstra?e 116, D-24118 Kiel, Germany
Phone: (+49) 431 5606-435, Fax: (+49) 431 5606-436
Mobile: (+49) 171 6921973, Web: http://www.schweigstill.de/